The present invention generally relates to vending machines and, more particularly, is concerned with a multiple coin actuation mechanism having a pivotal latch preventing coin removal from a carrier wheel recess.
U.S. Pat. Nos. 5,657,848 and 5,924,542 to Schwarzli disclose a prior art multiple coin actuation mechanism for a vending machine. The coin actuation mechanism has a front cover plate with first and second coin slots, a rotatable coin carrier wheel with first and second coin recesses angularly spaced apart on one face of the carrier wheel and aligned with the first and second coin slots of the cover plate when the carrier wheel is in a home position for the user to deposit a coin into each of the coin recesses, a rear retainer plate overlying the carrier wheel and fixedly attached to the front cover plate, and a rocker bar fixedly mounted on the rear retainer plate and having an end stop which normally extends through a hole in the rear retainer plate to adjacent a slot on the cover plate but not extended from the slot so as to intersect with the path of any coin moved into or removed from the first coin slot of the front cover plate which blocks movement or removal of the coin. When the carrier wheel is turned a cam on a ratchet wheel, which rotates with the carrier wheel, engages the rocker bar and causes it to deflect so as to project its end stop through the slot on the cover plate and across the coin path thereby blocking removal of the coin from the second coin recess of the carrier wheel through the first coin slot of the front cover plate. This action of the rocker bar and its end stop is synchronized by the cam to only occur when the coin in the second coin recess is aligned with the first coin slot. At all other times the rocker bar is undeflected and thus its end stop is withdrawn from extension through the slot. However, a problem with this design in that the use of the rocker bar coin blocking device increases the complexity and cost of the design over that of the conventional prior art coin actuation mechanisms.
U.S. Pat. No. 7,222,711 to Chang, the inventor herein, seeks to avoid the problem of the cited Schwarzli patents by employing a multiple coin actuation mechanism design that introduces a minimum of additions or modifications thereto. This patent employs a pivotal coin removal blocking latch and provides an edge notch defined adjacent to one side of the first coin recess in the carrier wheel which allows initial insertion of the first coin through the first coin slot into the first coin recess while preventing removal of the second coin from the second coin recess through the first coin slot when the carrier wheel is turned sufficiently to align the second coin recess with the first coin slot. However, the latch is normally in an outer initial home position in which it extends across the path movement of first coin insertion into the first coin slot. Thus, the latch will be contacted by the first coin and must be deflected out of the way by the first coin in order to achieve insertion of the first coin through the first coin slot into the first coin recess. Frequently, users inserting the first coin will think the latch is an obstruction that needs to be dealt with and some users may damage the machine in attempting to force the coin against the latch.
Consequently, the approach of neither of these above cited patents seems to provide the optimum solution for the problem at hand with respect to the general type of vending machine multiple coin actuation mechanism described above. Therefore, a need still exists for an approach which will provide a solution to the aforementioned problem in the prior art without introducing any new problems in place thereof.